1. Field of the Invention
The present invention relates to a microwave oven, and more particularly, to a microwave oven which has an improved configuration of its mounting bracket to couple a magnetron, generating high-frequency electromagnetic waves, to a waveguide, in order to reduce the number of operations to couple the magnetron to the waveguide, and which is adapted to be stable in a fixed state of the mounting bracket to obtain a more efficient cooling effect for the magnetron.
2. Description of the Prior Art
In general, a microwave oven is a cooking appliance which is intended to cook foods in a cooking chamber by intermolecular frictional heating of the foods, which is generated by repeatedly agitating the water molecules of the foods with high-frequency electromagnetic wave energy generated by a magnetron.
As illustrated in FIG. 1, such a conventional microwave oven includes an oven body 1 and a housing 2 adapted to cover both side faces and an upper face of the oven body 1. An internal space of the oven body 1, defined by the housing 2, is divided into two chambers, i.e., a cooking chamber 4 and an electric component compartment 5 by an inner case 3 such that the cooking chamber 4 is located in the inner case 3, and the electric component compartment 5 is disposed adjacent to a side surface of the inner case 3.
The cooking chamber 4 has a cooking tray 4a provided at its bottom surface, on which foods to be cooked are placed. The electric component compartment 5 has a magnetron 6 provided therein to generate high-frequency electromagnetic waves into the cooking chamber 4 receiving the foods, a high voltage transformer 5a and a high voltage condenser 5b. The electric component compartment 5 has a cooling fan 5C provided therein to prevent overheating of the magnetron 6, the high voltage transformer 5a and the like, and a waveguide 7 to guide high-frequency electromagnetic waves generated by the magnetron 6 into the cooking chamber 4. The waveguide 7 is mounted on a side wall of the inner case 3. Accordingly, the magnetron 6 is located in the electric component compartment 5 and is coupled to the waveguide 7 to generate and guide high-frequency electromagnetic waves into the cooking chamber 4. The waveguide 7 includes a mounting bracket 8 to fix the magnetron 6 thereto.
FIG. 2 specifically illustrates the mounting bracket 8 and the magnetron 6. As illustrated in the drawing, the mounting bracket 8 is typically made of a thin plate, and is centrally formed with a reception hole 8a into which an antenna 6c (described hereinafter) of the magnetron 6 is inserted. The mounting bracket 8 is provided around the reception hole 8a with a welding portion 8b at which the mounting bracket 8 is welded to the waveguide 7 coupled to the inner case 3. By welding the mounting bracket 8 to an inlet portion of the waveguide 7 at the rear face of its welding portion 8b, the mounting bracket 8 can be securely fixed to the waveguide 7. The welding portion 8b includes upper and lower extensions 8c and 8d, which extend upwardly and downwardly by certain lengths. The upper and lower extensions 8c and 8d are formed with two pairs of threaded holes 8e, with each of the extensions 8c and 8d having a pair of threaded holes 8e. 
The magnetron 6, which is fixed to the mounting bracket 8, comprises a main body 6a, and a coupling surface 6b defining the face of the main body 6a and to be in contact with the mounting bracket 8. The coupling surface 6b is centrally provided with the antenna 6c, which is inserted into the reception hole 8a of the mounting bracket 8 to emit high-frequency electromagnetic waves generated by the main body 6a of the magnetron 6 into the waveguide 7. The coupling surface 8b is provided at its upper and lower ends with two pairs of coupling extensions 6d and 6e, each end of the coupling surface 6b having a pair of coupling extensions 6d or 6e. The upper and lower coupling extensions 6d and 6e are formed with coupling holes 6f, which respectively correspond to the threaded holes 8e of the mourning bracket 8. Accordingly, the magnetron 6 is securely fastened to the mounting bracket 8 in such a way that after the magnetron 6 is positioned on the mounting bracket 8, such that the coupling holes 6f of the magnetron 6 are aligned with the threaded holes 8e of the mounting bracket 8, respectively, screws 9 are engaged with the threaded holes 8f via the coupling holes 6f. However, such a mounting bracket 8 has disadvantages as described hereinafter.
The mounting bracket 8 is adapted to securely support in such a way that four screws inserted into the coupling holes 6f of the magnetron 6 are tightened into the threaded holes 8e formed at the upper and lower extensions 8c and 8d. Since this coupling operation requires the four threaded holes 8e to be tightened with screws 9, respectively, it is difficult to improve productivity due to the increased number of coupling steps. In addition, four of the screws 9 must be tightened one by one in a predetermined order. To tighten the screws 9 into the threaded holes 8e, the position of the magnetron 6 must be precisely adjusted such that the coupling holes 6f of the magnetron 6 are aligned with the threaded holes 8e of the mounting bracket 8. To precisely position the magnetron 6 is considerably time-consuming, thereby causing difficulty in the assembling operation of the magnetron 6.
Furthermore, since the magnetron 6, which is coupled to the mounting bracket 8, exerts downward load due to its relatively heavy weight, the upper end of the magnetron 6 may be inclined away from the mounting bracket 8 and the welding portion 8b adjacent to the upper extension 8c may become separated from the waveguide 7. In addition, the lower end of the mounting bracket 8, which is extended downwardly, is apt to bend toward the waveguide 7.
As seen in FIG. 1, the cooling fan 5c serves to cool the magnetron 6, the high voltage transformer 5a and the like, by sending air introduced from the outside to the electric components. Since the coupling surface 6b of the magnetron 6 is hidden by the mounting bracket 8, the coupling surface 6b of the magnetron 6 is insufficiently cooled when compared to other portions of the magnetron 6. Hence, it is impossible to sufficiently cool the magnetron 6 due to the configuration of the mounting bracket 8.
Accordingly, it is an object of the present invention to provide a microwave oven with an improved mounting bracket, coupling a magnetron generating high-frequency electromagnetic waves to a waveguide, in order to reduce the number of operations required to couple the magnetron to a waveguide, and which is adapted to be stable in a fixed state of the mounting bracket to obtain a more efficient cooling effect for the magnetron.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and other objects of the present invention are achieved by providing a microwave oven comprising: an oven body; an inner case disposed in the oven body, which defines a cooking chamber therein and an electric component chamber at its outside; a mounting bracket attached to the electric component chamber, which is provided with one or more pockets and is provided near the pocket with a reinforcing section to prevent bending deformation of the mounting bracket, and a magnetron mounted on the mounting bracket, which has one or more coupling portions to be inserted into the pocket of the mounting bracket.
The pocket may be formed by providing a slit on the mounting bracket and bulging a side portion of the slit in a direction to form an inlet at the slit, and the reinforcing section may be formed by depressing a portion of the mounting bracket in the other direction.
The reinforcing section may be positioned to surround the upper portion and both sides of the pocket.
The number of the pockets may be two, and the reinforcing section may comprise an upper-reinforcing portion positioned above the pockets, a center-reinforcing portion positioned between the pockets, and side-reinforcing portions positioned at both outer sides of the pockets, which are integrally formed.
The mounting bracket may be provided with a through-hole to allow a coupling surface of the magnetron attached to the mounting bracket to be exposed to the inside of the electric component compartment.
The mounting bracket may comprise a hanging portion at its upper end, which extends along the upper surface of the inner case.